Apparatus and method for debundlizing filter tow



1955 A. H. AGETT 3,220,060

APPARATUS AND METHOD FOR DEBUNDLIZING FILTER TOW Filed Jan. 7, 1964 FIG.1

l2 FAST BELT IO I3 28 FAST ROLL SLOW ROLLS FAST ROLL FAST ROLL TOW PATH 32 s| ow BELT \BI 33 FEED ROLLS FIG 3 FAST ROLL FEED ROLLS LEGEND ALBERT H. AGETT EXTENSION INVENTOR AMARELAXATION Y ATTORNEYS United States Patent 3,220,060 APPARATUS AND METHOD FOR DEBUNDLIZING FILTER TOW Albert H. Agett, Kingsport, Tenn, assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Jan. 7, 1964, Ser. No. 336,296 6 Claims. (Cl. 1965) This invention relates to apparatus and method for debundlizing cigarette filter tow, useful for the preparat on of improved filter rods for cigarettes and other smoking articles.

It is apparent from the previous cigarette filter operations that the optimum utilization of crimped filter tow as regards the weight of the finished filter is accomplished when the filaments are debundlized under conditions which result in the minimum net filament crimp extension.

One method for debundlizing crimped tow by means of longitudinal extension of the two bundle as a whole is described in US. Patent 2,794,480. It has been found that the amount of longitudinal extension necessary to debundlize filaments by the method described in that patent sometimes results in a somewhat great filament crimp extension than may be desirable.

It is apparent, therefore, that the development of improved apparatus and method for debundlizing tow which either retains or reforms much of the longitudinal compactness due to crimp is very desirable. The present invention in its various embodiments provides the apparatus and methods for accomplishing this desirable result.

An object of the present invention is to provide improved apparatus and method for debundlizing crimped cigarette filter tow.

Another object of the present invention is to provide improved apparatus and method for debundlizing crimped multifilament cigarette filter tow which does not overstretch the tow during the debundlizing crimped multifilament cigarette filter tow which does not overstretch the tow during the debundlizing operation.

Other objects will appear hereinafter,

Basically, my invention involves the use of opposing belts or rolls, or combinations of the two, running at different speeds relative to each other in such a manner as to alternately tension and relax those crimped filaments with which the moving rolls or belts come into contact.

In the apparatus shown in FIG. 1, this is accomplished by passing the tow between two opposing belts running at diiferent speeds relative to each other. Alternate tension and relaxation is accomplished by forcing the two belts into contact one with the other at intervals by means of adjustable idler rolls or bars.

In the apparatus shown in FIG. 2, this is accomplished by employing a single continuous belt which conveys the tow at a desired rate. Superimposed upon this belt are several rolls so positioned that the tow lies between the surface of the roll and the surface of the belt at the point of mutual contact. These rolls may be aligned in the plane of the belt with their axes perpendicular to the direction of travel. The rolls are driven at difierent speeds relative to each other and also relative to the speed of the belt so that the tow is alternately tensioned and relaxed to various controllable degrees during its travel through the apparatus.

In the apparatus shown in FIG. 3, the endless belt of FIG. 2 is replaced by a large roll or drum and the smaller rolls of varying speed relatively both to each other and to the surface speed of the drum are positioned so that the tow passes along the surface of the drum and between it and the surfaces of the smaller rolls at their point of contact,

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In addition to the speed ratio, the clearance in the nip or the compression upon the nip is significant and is controlled by means of pneumatic or mechanical loading and/ or positioning imposed upon the small rolls of the three devices above described.

The present invention will be further understood by reference to the following detailed description and accompanying drawing in which:

FIG. 1 is an elevational view of one form of my novel apparatus which may be employed to carry out my novel method of treating crimped continuous multifilament cigarette filter tow comprising a plurality of rolls and a pair of endless belts.

FIG. 2 is an elevational view of another form of apparatus in accordance with my invention for debundlizing tow comprising a plurality of rolls and a single endless belt, and

FIG. 3 is an elevational view of yet another form of apparatus in accordance with my invention comprising a plurality of small rolls coacting with a large roll.

Referring to FIG. 1, the apparatus there shown comprises a pair of cooperating endless belts 10 and 11.

Belt 10 is positioned and turned by rolls 12 and 13 which are mounted in a horizontal plane either one or both of which may be driven in a clockwise direction by conventional means, not shown. The path of belt 10 is further defined by small rolls 14, 15, 16, 17 and 18. Idler rolls 19 and 20 are provided for purposes hereinafter described.

Belt 11 is positioned and turned by rolls 21 and 22 which are also mounted in a horizontal plane either one or both of which may be driven in a counterclockwise direction by conventional means, not shown, Belt 10 is moved at a faster rate than belt 11.

Small rolls 23, 24, 25, 26 and 27 are positioned to support belt 11 and coact with opposite rolls 14, 19, 16, 20 and 18 to provide compression on either or both of belts 10 and 11 as they pass therebetween.

Coacting feed rolls 28 and 29 draw a continuous, crimped multifilament tow from a supply source, not shown, and the tow is introduced between the pair of moving endless belts 10 and 11 as shown in FIG. 1.

Belt 10 is moved at approximately 250 f.p.m. and belt 11 is moved approximately 15% slower. The tow 30 is therefore relaxed in the ratch between small rolls 18-27 and 2026, it being influenced only by slower belt 11. However, in the ratch between small rolls 20-26 and 1625 the tow is stretched owing to the action of both belts passing between the nip of rolls 16-25. Then in the ratch between small rolls 16-25 and 19-24 the tow is again relaxed, being influenced only by the slower moving belt 11. It is again stretched in the ratch between small rolls 1924 and 14-23. The tow is finally relaxed as it leaves the nip of rolls 14-23, The resulting tow, by the stretching and relaxing action just described, is substantially debundlized and improved parallel, crimped multifilament tow results.

Referring to FIG. 2, the tow opening apparatus comprises an endless belt 31 positioned around rolls 32 and 33. Small rolls 34, 35, 36, 37 and 38 are adjustably positioned to press downwardly against belt 31. Tow 30 is drawn from a supply, not shown, by feed rolls 39 and 40 and is lntroduced between the above-mentioned small rolls and the belt 31. Belt 31 is rotated at approximately 220 f.p.m. Roll 35, 36 and 37 are rotated approximately at the same rate as belt 31 but rolls 34 and 38 are rotated approximately 15% faster. This difference in rotation causes the tow to relax on the belt between rolls 35 and 36 and 37 and 38 but to be tensioned between rolls 36 and 37. After passing roll 34 the tow is again relaxed. This operation produces a fully debundlized tow of excellent characteristics. On leaving this tow blooming device the tow may be conducted to a cigarette plug forming operation, not shown.

Referring to FIG. 3, the tow opening device thereshown comprises a roll of large diameter 41 having coacting small rolls 42, 43, 44, 45 and 46 associated therewith. Rolls 42, 44 and 46 are rotated at a rate faster than rolls 43 and 45, the latter being rotated at approximately the rate of large roll 41. Tow 30 is drawn from a supply source, such as a bale, not shown, by feed rolls 47 and 48 and passed between the large roll 41 and the associated small rolls. The debundlizing operation takes place as follows. That portion of the tow moving between fast roll 42 and slow roll 43 is retarded and is relaxed. However, when the same portion of the tow continues between slow roll 43 and fast roll 44 it becomes tensioned. Then, as it continues between fast roll 44 and slow roll 45, it again is relaxed. It is again tensioned when it passes between slow roll 45 and fast roll 46. The tow, on leaving the nip between rolls 46 and 41, is again permitted to relax. The large roll is preferably rotated at 220 f.p.1n., the slow rolls at 220 f.p.m. and fast rolls at I250 f.p.m.

The apparatus and process of my invention therefor operates under the principle of debundlizing by repeated intermittent extension, alternated with reformation of the crimped configurations in the tow by means of enhanced relaxation.

My invenion utilizes the benefits which are derived from applying the extending forces repeatedly in small increments rather than in one large increment, thus producing a debundlized tow containing substantially no shiners or married fibers and which retains a greater amount of the initial compaction due to crimp.

My apparatus and process will operate satisfactorily on tow composed of cellulose acetate or polyolefin continuous filaments.

Tows suitable for cigarette filters range from 45,000 to 160,000 total denier. The filament sizes normally available are 1.5, 3, 5, 8, 12, 16, 20 and 35 denier per filament and the tow may be made up between 5,000 and 100,000 filaments (preferably 20,000) of about 1.5 to 16 (preferably about 5) denier per filament or a total denier within the range of 80,000 to 250,000 (perferably 100,000). The crimps in the tow should range from 4 to 18 crimps per inch and 9 crimps per inch are preferable.

The preferred tow comprises continuous filaments of cellulose acetate which have been spun from a spinnerette, having a plurality of orifices therein, by the well-known dry spinning process and loosely drawn together in more or less parallel band-like association to form a continuous band which is termed a tow in the spinning industry. Such a cellulose acetate tow can be made, for example, by the dry spinning process described in US. Patents 2,000,047 and 2,000,048. The cellulose acetate from which the tow is manufactured may have an acetyl value of 38 to 41%, preferably 38.8 to 39.2%. The tow may be crimped by any suitable crimping process which can give the desired highly crimped filament tow. The tow may be advantageously supplied for use in my process in the form of a bale about 40 inches high, 25 inches wide, and 50 inches long which weighs 600 to 800 pounds. Such a bale contains a continuous tow of about 91,000 feet in length. Because the tow is compacted in the bale, entangled filaments are often present when the tow is drawn out of the bale in the usual manner. Tows of these characteristics are available in the market.

While several embodiments of the present invention are described herein, it is understood the principle of this invention may be carried out in a number of ways. This application is not limited, therefore, to the precise details disclosed, but it is intended to cover all variations and modifications therefore falling within the scope of the appended claims.

I claim:

1. A method for continuously debundlizing a moving continuous multifilament crimped tow having entangled filaments therein which comprises alternately subjecting substantially equal lengths and widths of the tow to relaxation and tension while held against a moving surface at spaced points to first compact the crimped tow lengthwise, and then to extend the crimped tow lengthwise whereby entangled filaments are separated and the tow becomes debundlized.

2. In a device for debundlizing continuous multifilament crimped tow, in combination, a first moving surface adapted to support and move the tow at a desired rate, a second moving surface in intermittent contact with said first moving surface and adapted to press the tow against said first moving surface at spaced apart portions thereof and means for driving said second surface at a rate faster than said first surface.

3. Ina device for debundlizing continuous multifilament crimped tow, in combination, a moving surface adapted to support and move the tow at a desired rate, a plurality of rolls spaced along the moving surface and positioned to press the tow against said moving surface, and means for driving alternate rolls at a rate faster than the remaining rolls.

4. In a device for debundlizing continuous multifilament crimped tow, in combination, a large roll adapted to support and move the tow at a desired rate, a plurality of small rolls spaced along the surface of the large roll and positioned to press the tow against said large roll, and means for driving alternate small rolls at a rate faster than the remaining small rolls.

5. In a device for debundlizing continuous multifilament crimped tow, in combination, a pair of coacting, adjacent, endless belts adapted to rotate in a manner to draw the tow therebetween, a first plurality of coacting rolls adapted to press therebetween adjacent surfaces of said pair of endless belts against the tow at spaced portions thereof, a second plurality of coacting rolls, a pair of which is spaced between adjacent pairs of said first plurality of rolls, and adapted to press the tow and only one of said belt surfaces therebetween, and means for rotating said first plurality of rolls at a rate faster than the rotation of said second plurality of rolls.

6. In a device for debundlizing continuous multifilament crimped tow, in combination, a pair of coacting, adjacent, endless belts adapted to rotate in a manner to draw the tow therebetween, a first plurality of coacting rolls adapted to press therebetween adjacent surfaces of said pair of endless belts against the tow at spaced portions thereof, a second plurality of coacting rolls, a pair of which is spaced between adjacent pairs of said first plurality of rolls, and adapted to press the tow and only one of said belt surfaces therebetween, a belt guide roll positioned remotely from each of said second plurality of coacting rolls adapted to maintain one of said belts out of contact with said coacting rolls, and means for rotating said first plurality of rolls at a rate faster than the rotation of said second plurality of rolls.

References Cited by the Examiner UNITED STATES PATENTS 3,032,829 5/ 1962 Mahoney et a1 19-65 3,044,145 7/1962 Tageret al.. 28-1 3,095,632 7/1963 Smith 19-65 X DONALD W. PARKER, Primary Examiner. 

2. IN A DEVICE FOR DEBUNDLIZING CONTINUOUS MULTIFILAMENT CRIMPED TOW, IN COMBINATION, A FIRST MOVING SURFACE ADAPTED TO SUPPORT AND MOVE THE TOW AT A DESIRED RATE, A SECOND MOVING SURFACE IN INTERMITTEN CONTACT WITH SAID FIRST MOVING SURFACE AND ADAPTED TO PRESS THE TOW AGAINST SAID FIRST MOVING SURFACE AT SPACED APART PORTIONS THEREOF AND MEANS FOR DRIVING SAID SECOND SURFACE AT A RATE FASTER THAN SAID FIRST SURFACE. 